Revert "Fixing up setting styles to invalidate on IE9."

lib/html/templates/html/impl/impl_CSSStyleDeclaration.darttemplate

Index: lib/html/templates/html/impl/impl_CSSStyleDeclaration.darttemplate
diff --git a/lib/html/templates/html/impl/impl_CSSStyleDeclaration.darttemplate b/lib/html/templates/html/impl/impl_CSSStyleDeclaration.darttemplate
index 0cb0a0f1ef81baeb7bd75ae3743d770d0821cd51..d928c1d05715c1967132518f4121e1a01da83942 100644
--- a/lib/html/templates/html/impl/impl_CSSStyleDeclaration.darttemplate
+++ b/lib/html/templates/html/impl/impl_CSSStyleDeclaration.darttemplate
@@ -23,18 +23,6 @@ class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 
 $!MEMBERS
 
-$if DARTIUM
-  void setProperty(String propertyName, String value, [String priority]) native "CSSStyleDeclaration_setProperty_Callback";
-$else
-  void setProperty(String propertyName, String value, [String priority]) native '''
-    this.setProperty(propertyName, value, priority);
-    // Bug #2772, IE9 requires a poke to actually apply the value.
-    if (this.setAttribute) {
-      this.setAttribute(propertyName, value);
-    }
-  ''';
-$endif
-
   // TODO(jacobr): generate this list of properties using the existing script.
     /** Gets the value of "animation" */
   String get animation =>